5 things to know about Ebola outbreak

FILE - In this undated file image by the CDC shows an ebola Virus. U.S. health officials on Thursday, July 31, 2014, warned Americans not to travel to the three African countries, hit by an outbreak of Ebola. The travel advisory applies to non-essential travel to Guinea, Liberia and Sierra Leone. (AP Photo/CDC, File)

Two Americans who had been working to treat Ebola patients in Africa have been stricken by the disease. Officials say they will be taken to Atlanta's Emory University Hospital in a tightly sealed isolation unit. The first is expected to arrive Saturday, and the other a few days later, according to hospital officials.

Here are five things to know about Ebola and how it is spread:

1. THE WEST AFRICA EBOLA OUTBREAK IS NOW THE LARGEST IN HISTORY. The current outbreak in Liberia, Guinea and Sierra Leone has sickened more than 1,300 people and killed more than 700 this year.

2. BUT SOME PEOPLE HAVE SURVIVED EBOLA. While the fatality rate for Ebola can be as high as 90 percent, health officials in the three countries say people have recovered from the virus and the current death rate is about 70 percent. Those who fared best sought immediate medical attention and got supportive care to prevent dehydration even though there is no specific treatment for Ebola itself.

3. EBOLA CAN LOOK A LOT LIKE OTHER DISEASES. The early symptoms of an Ebola infection include fever, headache, muscle aches and sore throat, according to the World Health Organization. It can be difficult to distinguish between Ebola and the symptoms of malaria, typhoid fever or cholera. Only in later stages do people with Ebola begin bleeding both internally and externally, often through the nose and ears.

4. EBOLA IS ONLY SPREAD THROUGH BODILY FLUIDS. The Ebola virus is not airborne, so people would have to come into contact with the bodily fluids of an infected person. These include blood, sweat, vomit, feces, urine, saliva or semen -- making transmission through casual contact in a public setting unlikely.

5. FEAR AND MISINFORMATION THOUGH IS MAKING THINGS WORSE. In each of the affected countries, health workers and clinics have come under attack from panicked residents who mistakenly blame foreign doctors and nurses for bringing the virus to remote communities. Family members also have removed sick Ebola patients from hospitals, including one woman in Sierra Leone's capital who later died. Police had to use tear gas to disperse others who attacked a hospital in the country.